The insulated gate bipolar transistor (IGBT) is a common power switching device controlled by a voltage, it has the features of a large input capacitance, a high input resistance, small drive current, fast speed, high withstand voltage, good thermal stability, a high work temperature, a simple control circuit and the like, so that it has become a mainstream device of the power electronics apparatus at the present stage. The reverse conducting insulated gate bipolar transistor is a novel IGBT device, which integrates an IGBT structure and a reverse conducting diode structure on a same chip. So it can improve the passage of non-balanced carriers and optimize the tail current. The reverse conducting IGBT device has many advantages such as a small size, a high power density, a low cost, a high reliability and the like.
A conventional manufacturing method for the back side structure of the reverse conducting IGBT includes: manufacturing a front side structure, grinding a silicon wafer, coating a photoresist or film on the front side, coating a photoresist on the back side, exposing, developing, afterwards doping P-type impurities by implantation, removing the front protection layer, annealing, performing a back side metallization process, then the manufacturing is completed. However, in this manufacturing method of the reverse conducting IGBT, the annealing temperature of the back side cannot be too high due to the limitation of the front structure, so that the activation efficiency of the N+ and P+ impurities is not high, affecting the performance of the manufactured reverse-conducting IGBT.